Results of an international campaign to photometrically monitor the unique pre-main sequence eclipsing object KH 15D are reported .
An updated ephemeris for the eclipse is derived that incorporates a slightly revised period of 48.36 d. There is some evidence that the orbital period is actually twice that value , with two eclipses occurring per cycle .
The extraordinary depth ( \sim 3.5 mag ) and duration ( \sim 18 days ) of the eclipse indicate that it is caused by circumstellar matter , presumably the inner portion of a disk .
The eclipse has continued to lengthen with time and the central brightness reversals are not as extreme as they once were .
V-R and V-I colors indicate that the system is slightly bluer near minimum light .
Ingress and egress are remarkably well modeled by the passage of a knife-edge across a limb-darkened star .
Possible models for the system are briefly discussed .